High intensity UV radiation ozone treatment of nanocrystalline TiO 2 layers for high efficiency of dye-sensitized solar cells

Abstract

We have improved the conversion efficiency of dye-sensitized solar cells (DSSCs) by using high intensity UV-ozone treatment on nanocrystalline TiO 2 layers after sintering. The UV light sources used had powers of 1650 W and 500 W. UV-ozone treatment of nanocrystalline TiO 2 layers was performed for 10 min with a fixed distance between TiO 2 layers and UV light source of about 3 cm. Experimental results indicate that photocurrent and power conversion efficiency of cells increased when using high power 1650 W and 500 W UV-ozone treatment on TiO 2 layers. The short circuit current density (J sc) increased to 25.29 ± 0.23 mA/cm 2 and 22.22 ± 0.47 mA/cm 2, the open circuit voltage (V oc) to 0.73 ± 0.02 V and 0.74 ± 0.02 V, the fill factor (FF) to 0.66 ± 0.01 and 0.71 ± 0.03 and the power conversion efficiency to 11.95 ± 0.45% and 11.12 ± 0.28% respectively. The DSSCs were characterized for absorption dye, chemical structure on nanocrystalline TiO 2 layer and electrochemical properties by UV-visible spectroscopy, XPS, XRD, contact angle measurement and impedance spectroscopy respectively. © 2012 Elsevier B.V. All rights reserved.